Non-cancerous blood-filled masses known as hemangiomas are the primary cause of lesions on the liver, according to the California Pacific Medical Center. Other benign causes of hepatic lesions include simple liver cysts, focal nodular hyperplasia, and hepatic adenomas, explains Johns Hopkins Medicine. Liver cancers such as hepatocellular carcinoma can cause malignant lesions on the liver, states the Cleveland Clinic. Liver lesions also appear when cancer from a nearby organ such as the colon metastasizes to the liver, notes WebMD.
Lesions on the liver are general anomalies in the tissue structure of the liver, notes WebMD. A hemangioma is a benign mass of anomalous blood vessels that is the most common cause of lesions on the liver, according to the American Liver Foundation and the California Pacific Medical Center. The second most commonly detected form of benign mass is a focal nodular hyperplasia, a tumor that does not require any treatment, explains the American Liver Foundation.
Other causes of lesions on the liver include cystic conditions such as simple non-infectious cysts and polycystic liver disease, explains the California Pacific Medical Center. Infectious cysts such as an amoebic liver abscess, bacterial pyogenic liver abscess or tapeworm-induced parasitic hydatid cysts also cause lesions on the liver. Malignant liver lesions are relatively rare but indicate the presence of liver cancers such as hepatocellular carcinoma, bile duct cancer or an aggressive form of liver cancer known as an angiosarcoma, explains the Cleveland Clinic.